Odor causing materials originate from a variety of sources in the environment. Odor materials must be capable of travelling through the air to activate the olfactory senses. However, the materials themselves may be solid, liquid, or gaseous. Odorous materials can originate from both organic and inorganic sources. Some examples of common odor causing materials in the environment are urine, feces, food waste, and bilge water.
Most odor causing materials generally contain similar or common types of odor causing molecules, such as, for example, skatoles, indoles, dimethyldisulfide, amines, and ammonia. Nature eliminates odors caused by these and other chemicals by slowly combining the materials that create odors with oxygen from the air. This process is called oxidation. The metal complexes of the present invention achieve the same results at a greatly increased rate of speed, within minutes or even seconds. One especially successful metal complex in the 1:1 dialkali monometal polyfunctional organic ligand chelate family is disodium monocopper (II) citrate dihydrate, CAS Registry #65330-59-8. This material is sold under the trademark NoRoma MCC.RTM. by Bio Systems Inc. of Cincinnati, Ohio.
One application for the metal complexes of this invention is in controlling odors in portable toilets and toilets used in the transportation industry, e.g. locomotives, passenger cars, airplanes, etc. There has been interest in these compounds for use by coroners, morgues, and funeral homes. This material may also be used to eliminate human scent which could be a boon during activities such as hunting. These metal complexes work especially well in neutralizing odors caused by sulfurous compounds and other nitrogen containing substances such as ammonia and skatoles, as well as hydrogen sulfide. It is seen that these metal complexes have a wide variety of industrial applications, as well as environmentally beneficial uses.
Another industrial application would be in removing ammonia odors. Ammonia is used in refrigeration coils and commercial freezers and tends to leak into the environment. Air, concentrated with ammonia gas is unsuitable for supporting life and this contaminated air can be cleared by atomizing an appropriate mixture containing monocopper citrate into the contaminated air the form of a fine dispersion of droplets. This particular application is remarkable in that the operation typically occurs in an environment where the temperature is below -20.degree. F. Therefore, it is seen that the metal complexes of this invention are useful under a whole host of environmental conditions.
U.S. Pat. No. 4,278,610 to Maurer, et al. (the '610 patent), discloses a method of making an organic metal salt or complex. The generic chemical compound is described in this patent as is the chemical reaction used to make it. The entire disclosure of the '610 patent is incorporated herein by reference.
U.S. Pat. No. 4,180,473 to Maurer, et al. (the '473 patent), discloses a method of transporting metal ions introducing a metal complex into a medium containing a moiety which medium has an affinity for the metal ion. The complex releases the ion in a controlled manner upon demand by the medium. The '473 patent uses disodium monocopper citrate, or MCC, as an example of chemical that can be used to deliver metal ions, in this case copper, to a system that requires the metal ion. The '473 patent describes a variety of situations where the metal ion is either desirable or necessary. Metal machining operations and control of microbiological activities are among some of the examples of systems that need or benefit from the copper ion distributed from a metal complex such as MCC. The odor controlling characteristics of MCC are not discussed nor are they suggested in either the '473 or '610 patents. Also there is no discussion of these characteristics in any other known literature. The entire disclosure of the '473 patent is incorporated herein by reference.